Selective-speed telegraph code instruction system



May 20, 1947. o. THOMPSON SELECTIVE-SPEED TELEGRAPH CODE INSTRUCTIONSYSTEM Filed. NOV. 14, 1942 TONE INPUT DUDDDDIJUDUU XMM Oraz'lle J.Tfzom 5027/ Ms Ufa/away Patented May 20, 1947 SELECTIVE-SPEED TELEGRAPHCODE INSTRUCTION SYSTEM Orville I. Thompson, Chicago, 111., assignor toDe Forest's Training, 'Inc., Ghicago, 111., a corporation of IllinoisApplication November 14, 1942, Serial No. 465,596

ticularly to an apparatus whereby a plurality of code speeds may beautomatically transmitted simultaneously by a single sending unit.

It is a principal object of this invention to provide a manifold codespeed transmission device which is simple in construction, economical inmanufacture and highly efiicient in use.

Another object of this invention is to provide a single signal bearingmeans bearing a plurality of signals at graduated speeds and operativeby a common drive for simultaneously transmitting a plurality of signalseach at a different ratio of words per minute.

A further object of this invention is to provide a device on which thesound of code characters can be made the same for a wide range of codespeeds.

Other objects and advantages of the invention will appear hereinafter.

The invention consists in' the novel combination and arrangement ofparts to be hereinafter described and claimed.

The invention will be best understood by reference to the accompanyingdrawings showing the preferred form of construction, and in which:

Fig. 1 is a schematic diagram of a multi-speed code sending systemembodying my invention;

Fig. 2 is a fragmentary perspective view .of a gang sound-sensitive unitembodied in my invention;

Fig. 3 is a fragmentary vertical sectional View through a drive meansand associated parts embodied in my invention;

Fig. 4 is a fragmentary vertical section through an individual signaldetector device employed in my invention;

Fig. 5 is a view of a portion of signal bearing tape illustrating thegraduated signallimprinted on the tape; and

Fig. 6 is a schematic diagram of another form of signal distributingsystem which may be used with my invention.

Heretoforein thepractice of code instruction,

various types of automatic senders have been used whereby to transmitcode messages :from a code bearing strip 1 or :drum :to receivingstations.

However, all existing automaticsenders are'limited to the sending of asingle message and are set to a desired speed by the driving means forthe code bearing members. Such devices are best represented by thedisclosure in Patent No. 2,284,024 issued May 26, 1942, to Stevens onTape actuated reproducer, etc. These former automatic senders required aseparate drive and an individual code bearing tape for each of the codespeeds, which, for example, might range from six to sixty words perminute at two-word intervals, thus requiring separate sending units inan instructionsystem in order that all code speeds might be availablefor sending simultaneously during a course of instruction.

This invention contemplates the provision of an. automatic code sendingapparatus whereby the full range of code speeds will be automaticallytransmitted simultaneously by the use of a multitracked tape driven by asingle drive means. In carrying out the invention 1' provide a framestructure Ill upon which is mounted a motor H or any other suitablepower transmission means. A drive shaft I2 extending from the motor I!has bearing in the frame It and carries on its outer end for rotationtherewith a reel or spool [3 on which a web M in the form of transparenttape may be wound. A feed roller l5 in the form of a reel is mounted onthe frame Ill through the medium of a shaft l6 carried by the frame l Gand has wound thereupon the web [4 for feeding the latter in accordancewith the speed of the reel I3 under power of the driving motor ii.

Arranged between the feeding roller l5 and the driving reel [3 isaninsulated panel H which is supported upon brackets I8 attached to theframe [0; this panel supports a plurality of light-sensitive units l9which correspond in number to the number of different speeds of messageto be transmitted. It is apparent that any numberof units I9 may beemployed and, as heretofore explained, that the range may be from sixwords per minute on up, at varied intervals of words per minute.However, for the present description only five units I9 are shown toillustrate the principle of the invention.

Each light-sensitive-unit L9 comprises a socket '29 mounted upon thepanel [fl-to disposea-receiving seat :2I on. the side of the panel so tolaterally support, a photo-electric cell the plane of movement of thewebMr'frcm'faading roller to driving roller l3. Each unit [9 is completedby having a tubular light shield 23 arranged on the socket 20 tosurround the respective photo-electric cell 22'. As shown in thedrawing, the light-sensitive units are arranged with their centersspaced equidistant on a segmental arc and thus together form a guidewayover which the web l4 may be trained. A floating sprocket 24 is arrangedon the frame II] for rotative movement adjacent the feeding roller I andis adapted to guide the web M from a uniform position over thelight-sensitive units I9, the web traveling around the guideway formedby the units onto another floating sprocket 25 which is carried by theframe If) and acts as, a tensioner for the web 14 to assure at all timesthat it will cling to the light-sensitive units for reasons hereinafterto become more apparent; the web finally being aflixed to the drivingreel I3 in a Well-known manner, the reel l3 being driven by motor H topull the web over the aforesaid train of movement.

In carrying out the principle of this invention, I provide the web Mwith a number of tracks 26 which correspond in number with the number ofspeed variations desired. Each of the tracks 26 comprises a message incode by printing, perforating or otherwise marking the hieroglyphics ofthe code along the tracks. As shown in Fig. 5, the web l4 comprises aCelluloid ribbon having eight different tracks 26 each bearing amessage. In this form of web the message is recorded by photography, andwhile this is a very practical method of recording the messages on theweb, it is essential to this invention that the production of the codeon the web be done at a fixed linear speed but in a manner to rendereach track 26 a different code speed with respect to each other. Thus,as seen in Figs. 2 and 5, the same code character starting from a fixedpoint on the web will be of increased spacing along its respective trackin proportion to the ratio of number of words per minute. The lowermosttrack 26 (Fig. 5) represents a code message which will bear six wordsrequiring a minute of travel of the web to pass a fixed point. Eachtrack from bottom to top increases in speed by a speed of two words aminute so that the uppermost track 25 represents a code speed of twentywords per minute of travel of the web past a fixed point.

Thus, as seen in Figs. 2 and 5, the code characters remain-the same butthe characters of one track 28 are spaced from succeeding characters agreater or lesser distance with respect to the spacing of characters onadjacent tracks, thus assuring at all times that each character,regardless of whichever sound track it be on, will be of a constantphonetic pitch. In former type tapes with a single track, a change ofspeed of travel of the tape although changing the number of words perminute in transmission had the undesirable characteristic of likewisechanging the tone pitch of eachcharacter. Since it is important that thestudent at an early state become accustomed to the uniform tone pitch atwhich telegraphic code is transmitted it is a great advantage that hereceive the message at such uniform tone pitch at a greater or lessernumber of characters per minute. It is therefore obvious that in thepresent invention it is an advantage in having numerous tracks withcharacters each of which will transmit a constant tone value regardlessof the number of words transmitted per minute.

Each of the light shields 23 has an aperture 21 formed therein in itsside wall along which the web [4 travels. When considering thelightsensitive units as a gang as shown in Fig. 2, each aperture 21 isspaced relative to the aperture 2'! of the adjacent unit l9 a distancecorresponding to the distance between tracks 26 on the Web Id. In thismanner each track 26 cooperates with its respective aperture 21 toaffect a separate light-sensitive unit. In conjunction with theapertures 21 and code tracks 26, there is a light source 28 arranged ona bracket 29 carried by the frame Ill. A reflector 30 shields the lightsource 28 but permits the light to be reflected in the direction of theapertures 21 so that when a clear image is presented on the track 26,light will impinge upon the photo-electric cell 22 to excite electronicactivity within the cell 22 to permit an impulse to bridge the anode andcathode of the cell 22.

As shown in Fig. 1 of the drawing, each photoelectric cell 22 isarranged in a block grid keying tube circuit 3! in a manner such thatwhen an impulse is permitted to pass through the cell as aforesaid, ablocking tube 32 is caused to operate, which operation will permittransmission of the signal to head phones Each circuit is provided witha commutator switch 34 whereby the different photo-electric cells may bethrown in circuit with a particular receiving set. As illustrated,station "1 on the left of Fig. 1 is connected in circuit with thelowermost photoelectric cell 22 and is receiving the slowest messagefrom the web, while station 5 is receiving the fastest message, all ofwhich is governed by the position of the pointer on the commutatorswitch 34.

In Fig. 6, a similar circuit may be employed; however, in this systemthe blocking or keying tubes are all built in a single unit 35 eachhaving a series of jacks 36 whereby plugs 31 from the receiving stationsmay be plugged in to connect such stations to the photo-electric cell ofthe code speed desired.

It is obvious that various forms of circuits may be employed and thatthey may be amplified depending upon the form of reception desired, themain purpose being to pick up the message in a manner to carry out myinvention of producing the simultaneous transmission of several codemessages at different code speeds from a single automatic code sender.

While I have illustrated and described the preferred form ofconstruction for carrying my invention into eifect, this is capable ofvariation and modification without departing from the spirit of theinvention. I, therefore, do not wish to be limited to the precisedetails of construction set forth, but desire to avail myself of suchvariations and modifications as come within the scope of the appendedclaim.

Having thus described my invention, what I claim as new and desire toprotect by Letters Patent is:

A device of the class described comprising a plurality of independentlyoperated receiving stations, means for transmitting a plurality of codemessages, means for connecting said receiving stations to saidtransmitting means for the transmission by said transmitting means toone or more of said receiving stations of a selected one of said codemessages, said code messages varying in speed by a single drive means,said transmitting means including a plurality of message transmittingunits arranged adjacent each other to form a guideway, a web arrangedfor movement over said guideway, a plurality of message tracksREFERENCES CITED formed in said web and spaced relative to each Thefollowing references are of record in the othe}:s transversely of saidweb, said message file of this patent:

trac being made up of code characters with 5 the message tracks varyingin characters per UNITED STATES PATENTS length of said web with respectto each other, Number Name Date means on said message transmitting unitsfor 680,695 Comins Aug. 20, 1901 communicating a particular one of saidmessage 1,804,136 Wright May 5, 1931 transmitting units with aparticular message 10 2,284,024 Stevens May 26, 1942 track, and drivemeans for moving said web rela- 1,848,799 Papalia Mar. 8, 1932 tive tosaid guideway. 1,962,467 ShOlkin June 12, 1934 ORVILLE I. THOMPSON.1,950,011 Soheibell Mar. 6, 1934

